Oxygen peroxide

Acrylic acid derivatives. Acrylic esters polymerise readily under the influence of oxygen, peroxides, light or heat to give colourless, glass-Uke plastics. 

High pressure (60—350 MPa) free-radical polymerization using oxygen, peroxide, or other strong oxidizers as initiators at temperatures of up to 350°C to produce low density polyethylene (LDPE), a highly branched polymer, with densities from 0.91 to 0.94 g/cm. ... 

A leaking valve allowed butadiene to accumulate in a pipeline exposed to an inerting gas containing up to 2% of oxygen. Peroxide formed and initiated popcorn polymerisation which burst the pipeline. 

Laboratory and industrial-scale processes show that acetylene is one intermediate in carbon formation in the combustion of petroleum hydrocarbons. This is not only a result of thermal decomposition but a part of the complex of reactions occurring in the oxidation system. Steps resulting in the immediate production of acetylene seem to be molecular decomposition of molecules, or free radicals, or dehydrogenation, followed by combination or addition of oxygen. Peroxide formation may occur also. These reactions may be a general source of the hydrocarbon flame bands. 

The reaction is exothermic and may form polymer from a molecular weight of 1000 to well over 1 million. The high-pressure process, which normally produces types I and II, uses oxygen, peroxide, or other strong oxidizers as catalyst. Pressure of reaction ranges from 15.000 to 50.000 psi ( 1,020-3,400 atmospheres). The polymer formed in this process is highly branched, with side branches occurring every 15-40 carbon atoms on the. chain backbone. Ciystallinity of this polyethylene is approximately 40-60%, Amorphous content of the polymer increases as the density rs reduced,... 

Catalytic oxidations by copper compounds are mainly homolytic in nature. Copper salts have been extensively used in conjunction with molecular oxygen, peroxides and persulfate for the oxidation of a variety of alkenic and aromatic hydrocarbons.56,584... 

Only a few of rather numerous reactions of oxidation of alkoxides by oxygen, peroxides, halogens, and other compounds may be used for synthesis of M(OR) (with considerable yields). These reactions are known for uranium alkoxides [197, 856], such as... 

Reactions with electrophilic substrates. Oxygen peroxide formed during the development of the early products and hydroperoxides can attack electrophilic substrates according to an ionic, nonradical reaction. In this way, carbon-carbon double bonds can be transformed into epoxides and tertiary amines into N-oxides. These are cooxidations with an ionic mechanism. 

Note Colorless, odorless (when pure), hygroscopic liquid, powerful aprotic solvent dissolves many inorganic salts, soluble in water combustible readily penetrates the skin incompatible with strong oxidizers and many halogenated compounds (e.g., alkyl halides, aryl halides), oxygen, peroxides, diborane, perchlorates. Synonyms DMSO, methyl sulfoxide, sulfinylbismethane. 

Vinylene carbonate is one of the few 1,2-disubstituted ethylenes that is known to undergo facile radical initiated homopolymerization. Initiation may be by oxygen, peroxides or cobalt-60 y-radiation. Such polymers are reportedly useful as coatings and films. Vinylene carbonate also copolymerizes with ethylene under high pressure to yield a material with about 10% vinylene carbonate content. This polymer, when blended with polyvinyl chloride, is suitable for injection molding. 

Trialkyl boron was first claimed as a new anionic initiator for the polymerization of vinyl compounds (264), although it was rather improbable in view of the low ionic character of the boron-carbon bond. The error was quickly corrected when it was shown that free radicals were involved (265, 266) and that oxygen, peroxides, silver salts and copper salts were co-catalysts (262, 267). Aluminum alkyls can also initiate radical polymerizations in the presence of oxygen (267,262) but, as in the case of zinc, cadmium or boron alkyls, the products were not stereoregular. Thus, complexing between catalyst and monomer probably does not occur. 

At concentrations of 0.25 and 0.50%, the zinc acetate behaved like the hindered-amine stabilizer—it afforded little or no photochemical protection to the wool fabric AE values of 2.47 and 2.21 were observed at the above concentrations after 550 kj/m2 exposure. Thus, one could assume it functions photochemically as an oxygen/peroxide scavenger. At concentrations of 1.0%, zinc acetate did afford moderate protection to the wool fabrics (AE value of 1.55 after 550 kj/m2 exposure), but its absorption/transmission curve exhibited a maximum absorption only at 250-300 nm. Thus, the moderate protection afforded to the wool fabric... 

In the absence of oxygen, peroxides react with iodide in a 1 1 stoichiometric relationship and liberate iodine (Lea, 1931 1952) ... 

There are some surface oxygen anionic vacancies [83, 90, 91, 92]. These vacancies induce formation of surface oxygen peroxide or superoxide close to the... 

The presence of greater than 5% water in solutions that contain trichloromonofluoromethane may lead to hydrolysis of the propellant and the formation of traces of hydrochloric acid, which may be irritant to the skin or cause corrosion of metallic canisters. Trichloromonofluoromethane may also react with aluminum, in the presence of ethanol, to cause corrosion within a cylinder with the formation of hydrogen gas. Similarly, alcohols in the presence of trace amounts of oxygen, peroxides. 

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